col: tidy up sources a little bit

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/text-utils/col.c b/text-utils/col.c
index 6488688193848afea69136fc587748c9f270801a..d3dd647be6a57ebc887d6a2a2cf05924af9b54e0 100644 (file)
--- a/text-utils/col.c
+++ b/text-utils/col.c
@@ -53,33 +53,35 @@
  * See Documentation/deprecated.txt for more information.
  */
 
-#include <stdlib.h>
-#include <errno.h>
 #include <ctype.h>
-#include <string.h>
+#include <errno.h>
+#include <getopt.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
-#include <getopt.h>
 
-#include "nls.h"
-#include "xalloc.h"
-#include "widechar.h"
-#include "strutils.h"
 #include "closestream.h"
+#include "nls.h"
 #include "optutils.h"
+#include "strutils.h"
+#include "widechar.h"
+#include "xalloc.h"
 
-#define        BS      '\b'            /* backspace */
-#define        TAB     '\t'            /* tab */
 #define        SPACE   ' '             /* space */
+#define        BS      '\b'            /* backspace */
 #define        NL      '\n'            /* newline */
 #define        CR      '\r'            /* carriage return */
+#define        TAB     '\t'            /* tab */
+#define        VT      '\v'            /* vertical tab (aka reverse line feed) */
+
 #define        ESC     '\033'          /* escape */
-#define        SI      '\017'          /* shift in to normal character set */
-#define        SO      '\016'          /* shift out to alternate character set */
-#define        VT      '\013'          /* vertical tab (aka reverse line feed) */
-#define        RLF     '\007'          /* ESC-07 reverse line feed */
-#define        RHLF    '\010'          /* ESC-010 reverse half-line feed */
-#define        FHLF    '\011'          /* ESC-011 forward half-line feed */
+#define        RLF     '\a'            /* ESC-007 reverse line feed */
+#define        RHLF    BS              /* ESC-010 reverse half-line feed */
+#define        FHLF    TAB             /* ESC-011 forward half-line feed */
+
+#define        SO      '\016'          /* activate the G1 character set */
+#define        SI      '\017'          /* activate the G0 character set */
 
 /* build up at least this many lines before flushing them out */
 #define        BUFFER_MARGIN           32
@@ -87,6 +89,7 @@
 /* number of lines to allocate */
 #define        NALLOC                  64
 
+/* SI & SO charset mode */
 typedef enum {
        CS_NORMAL,
        CS_ALTERNATE
@@ -163,7 +166,7 @@ static void __attribute__((__noreturn__)) usage(void)
 
        fputs(USAGE_SEPARATOR, out);
        fprintf(out, _(
-               "%s reads from standard input and writes to standard output\n\n"),
+               "%s reads from standard input and writes to standard output\n"),
                program_invocation_short_name);
 
        printf(USAGE_MAN_TAIL("col(1)"));
@@ -173,7 +176,7 @@ static void __attribute__((__noreturn__)) usage(void)
 static inline void col_putchar(wchar_t ch)
 {
        if (putwchar(ch) == WEOF)
-               errx(EXIT_FAILURE, _("write error"));
+               err(EXIT_FAILURE, _("write failed"));
 }
 
 /*
@@ -229,7 +232,7 @@ static void flush_line(struct col_ctl *ctl, LINE *l)
                }
                if (count_size <= l->l_max_col) {
                        count_size = l->l_max_col + 1;
-                       count = xrealloc((void *)count, sizeof(size_t) * count_size);
+                       count = xrealloc(count, sizeof(size_t) * count_size);
                }
                memset(count, 0, sizeof(size_t) * l->l_max_col + 1);
                for (i = nchars, c = l->l_line; c && 0 < i; i--, c++)
@@ -254,18 +257,21 @@ static void flush_line(struct col_ctl *ctl, LINE *l)
        while (0 < nchars) {
                this_col = c->c_column;
                endc = c;
+
+               /* find last character */
                do {
                        ++endc;
                } while (0 < --nchars && this_col == endc->c_column);
 
-               /* if -b only print last character */
                if (ctl->no_backspaces) {
+                       /* print only the last character */
                        c = endc - 1;
                        if (0 < nchars && endc->c_column < this_col + c->c_width)
                                continue;
                }
 
                if (last_col < this_col) {
+                       /* tabs and spaces handling */
                        ssize_t nspace = this_col - last_col;
 
                        if (ctl->compress_spaces && 1 < nspace) {
@@ -284,6 +290,7 @@ static void flush_line(struct col_ctl *ctl, LINE *l)
                }
 
                for (;;) {
+                       /* SO / SI character set changing */
                        if (c->c_set != ctl->last_set) {
                                switch (c->c_set) {
                                case CS_NORMAL:
@@ -297,7 +304,11 @@ static void flush_line(struct col_ctl *ctl, LINE *l)
                                }
                                ctl->last_set = c->c_set;
                        }
+
+                       /* output a character */
                        col_putchar(c->c_char);
+
+                       /* rubout control chars from output */
                        if (c + 1 < endc) {
                                int i;
 
@@ -349,7 +360,7 @@ static void flush_lines(struct col_ctl *ctl, ssize_t nflush)
                        flush_line(ctl, l);
                }
                ctl->nblank_lines++;
-               free((void *)l->l_line);
+               free(l->l_line);
                free_line(ctl, l);
        }
        if (ctl->lines)
@@ -359,9 +370,9 @@ static void flush_lines(struct col_ctl *ctl, ssize_t nflush)
 static int handle_not_graphic(struct col_ctl *ctl, struct col_lines *lns)
 {
        switch (lns->ch) {
-       case BS:                /* can't go back further */
+       case BS:
                if (lns->cur_col == 0)
-                       return 1;
+                       return 1;       /* can't go back further */
                if (lns->c)
                        lns->cur_col -= lns->c->c_width;
                else
@@ -370,8 +381,8 @@ static int handle_not_graphic(struct col_ctl *ctl, struct col_lines *lns)
        case CR:
                lns->cur_col = 0;
                return 1;
-       case ESC:               /* just ignore EOF */
-               switch (getwchar()) {
+       case ESC:
+               switch (getwchar()) {   /* just ignore EOF */
                case RLF:
                        lns->cur_line -= 2;
                        break;
@@ -479,6 +490,7 @@ static void update_cur_line(struct col_ctl *ctl, struct col_lines *lns)
 
        lns->this_line = lns->cur_line + lns->adjust;
        nmove = lns->this_line - lns->nflushd_lines;
+
        if (0 < nmove && ctl->max_bufd_lines + BUFFER_MARGIN <= (size_t)nmove) {
                lns->nflushd_lines += nmove - ctl->max_bufd_lines;
                flush_lines(ctl, nmove - ctl->max_bufd_lines);
@@ -570,6 +582,7 @@ int main(int argc, char **argv)
 
        while (feof(stdin) == 0) {
                errno = 0;
+               /* Get character */
                if ((lns.ch = getwchar()) == WEOF) {
                        if (errno == EILSEQ) {
                                warn(_("failed on line %lu"), lns.max_line + 1);
@@ -577,15 +590,16 @@ int main(int argc, char **argv)
                        }
                        break;
                }
-               if (!iswgraph(lns.ch) &&
-                   handle_not_graphic(&ctl, &lns))
+
+               /* Deal printable characters */
+               if (!iswgraph(lns.ch) && handle_not_graphic(&ctl, &lns))
                        continue;
 
                /* Must stuff ch in a line - are we at the right one? */
                if ((size_t)lns.cur_line != lns.this_line - lns.adjust)
                        update_cur_line(&ctl, &lns);
 
-               /* grow line's buffer? */
+               /* Does line buffer need to grow? */
                if (ctl.l->l_lsize <= ctl.l->l_line_len + 1) {
                        size_t need;
 
@@ -593,14 +607,18 @@ int main(int argc, char **argv)
                        ctl.l->l_line = xrealloc(ctl.l->l_line, need * sizeof(CHAR));
                        ctl.l->l_lsize = need;
                }
+
+               /* Store character */
                lns.c = &ctl.l->l_line[ctl.l->l_line_len++];
                lns.c->c_char = lns.ch;
                lns.c->c_set = lns.cur_set;
+
                if (0 < lns.cur_col)
                        lns.c->c_column = lns.cur_col;
                else
                        lns.c->c_column = 0;
                lns.c->c_width = wcwidth(lns.ch);
+
                /*
                 * If things are put in out of order, they will need sorting
                 * when it is flushed.
@@ -612,6 +630,7 @@ int main(int argc, char **argv)
                if (0 < lns.c->c_width)
                        lns.cur_col += lns.c->c_width;
        }
+
        /* goto the last line that had a character on it */
        for (; ctl.l->l_next; ctl.l = ctl.l->l_next)
                lns.this_line++;